A crash on a French motorway which killed a British father and two of his children may have been caused by him falling asleep or being distracted, investigators have said.

The driver's wife and their youngest child were flown to hospital following the crash which happened after 7am on Sunday on the A39 in Beaurepaire-en-Bresse between Lyon and Dijon. The youngster was thought to be seriously injured.

Two air ambulances were called to the scene and the injured child was flown to hospital in Lyon.

In an interview with the France3 TV channel, a member of the emergency services said two of the children were dead when they arrived and the father was trapped.

He was said to have died from a heart attack minutes after he was released from the wreckage.

Pictures showed a badly mangled family Nissan which was ripped apart after initially hitting a safety barrier.

An investigator told the TV channel the reason for the car hitting the barrier was as yet unknown, but it could have been caused by the driver falling asleep or being distracted.

The Foreign Office was understood to be offering assistance.

A Foreign Office spokeswoman said: "We are providing assistance following a road traffic accident in France, in which three British nationals have sadly died and two others have been hospitalised.

"We are working closely with local authorities and supporting the families at this difficult time."